package com.yiruantong.common.mybatis.handler;

import cn.hutool.core.annotation.AnnotationUtil;
import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.collection.ConcurrentHashSet;
import cn.hutool.core.util.ArrayUtil;
import cn.hutool.core.util.ClassUtil;
import cn.hutool.core.util.ObjectUtil;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.JSQLParserException;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.Parenthesis;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import com.yiruantong.common.core.domain.dto.RoleDTO;
import com.yiruantong.common.core.domain.model.LoginUser;
import com.yiruantong.common.core.exception.ServiceException;
import com.yiruantong.common.core.utils.SpringUtils;
import com.yiruantong.common.core.utils.StreamUtils;
import com.yiruantong.common.core.utils.StringUtils;
import com.yiruantong.common.mybatis.annotation.DataColumn;
import com.yiruantong.common.mybatis.annotation.DataPermission;
import com.yiruantong.common.mybatis.enums.DataScopeType;
import com.yiruantong.common.mybatis.helper.DataPermissionHelper;
import com.yiruantong.common.satoken.utils.LoginHelper;
import org.springframework.context.expression.BeanFactoryResolver;
import org.springframework.expression.BeanResolver;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.ParserContext;
import org.springframework.expression.common.TemplateParserContext;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.expression.spel.support.StandardEvaluationContext;

import java.lang.reflect.Method;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;

/**
 * 数据权限过滤
 *
 * @author YiRuanTong
 * @version 3.5.0
 */
@Slf4j
public class PlusDataPermissionHandler {

  /**
   * 方法或类(名称) 与 注解的映射关系缓存
   */
  private final Map<String, DataPermission> dataPermissionCacheMap = new ConcurrentHashMap<>();

  /**
   * 无效注解方法缓存用于快速返回
   */
  private final Set<String> invalidCacheSet = new ConcurrentHashSet<>();

  /**
   * spel 解析器
   */
  private final ExpressionParser parser = new SpelExpressionParser();
  private final ParserContext parserContext = new TemplateParserContext();
  /**
   * bean解析器 用于处理 spel 表达式中对 bean 的调用
   */
  private final BeanResolver beanResolver = new BeanFactoryResolver(SpringUtils.getBeanFactory());

  public PlusDataPermissionHandler() {
    // 排除掉SqlRunner的操作
    invalidCacheSet.add("com.baomidou.mybatisplus.core.mapper.SqlRunner.SelectList");
  }

  public Expression getSqlSegment(Expression where, String mappedStatementId, boolean isOr) {
    DataColumn[] dataColumns = findAnnotation(mappedStatementId);
    if (ArrayUtil.isEmpty(dataColumns)) {
      invalidCacheSet.add(mappedStatementId);
      return where;
    }
    LoginUser currentUser = DataPermissionHelper.getVariable("user");
    if (ObjectUtil.isNull(currentUser)) {
      currentUser = LoginHelper.getLoginUser();
      DataPermissionHelper.setVariable("user", currentUser);
    }
    // 如果是超级管理员或租户管理员，则不过滤数据
    if (LoginHelper.isSuperAdmin() || LoginHelper.isTenantAdmin()) {
      return where;
    }
    String dataFilterSql = buildDataFilter(dataColumns, isOr);
    if (StringUtils.isBlank(dataFilterSql)) {
      return where;
    }
    try {
      Expression expression = CCJSqlParserUtil.parseExpression(dataFilterSql);
      // 数据权限使用单独的括号 防止与其他条件冲突
      Parenthesis parenthesis = new Parenthesis(expression);
      if (ObjectUtil.isNotNull(where)) {
        return new AndExpression(where, parenthesis);
      } else {
        return parenthesis;
      }
    } catch (JSQLParserException e) {
      throw new ServiceException("数据权限解析异常 => " + e.getMessage());
    }
  }

  /**
   * 构造数据过滤sql
   */
  private String buildDataFilter(DataColumn[] dataColumns, boolean isOr) {
    // 更新或删除需满足所有条件
    String joinStr = isOr ? " OR " : " AND ";
    LoginUser user = DataPermissionHelper.getVariable("user");
    StandardEvaluationContext context = new StandardEvaluationContext();
    context.setBeanResolver(beanResolver);
    DataPermissionHelper.getContext().forEach(context::setVariable);
    Set<String> conditions = new HashSet<>();
    for (RoleDTO role : user.getRoles()) {
      user.setRoleId(role.getRoleId());
      // 获取角色权限泛型
      DataScopeType type = DataScopeType.findCode(role.getDataScope());
      if (ObjectUtil.isNull(type)) {
        throw new ServiceException("角色数据范围异常 => " + role.getDataScope());
      }
      // 全部数据权限直接返回
      if (type == DataScopeType.ALL) {
        return "";
      }
      boolean isSuccess = false;
      for (DataColumn dataColumn : dataColumns) {
        if (dataColumn.key().length != dataColumn.value().length) {
          throw new ServiceException("角色数据范围异常 => key与value长度不匹配");
        }
        // 不包含 key 变量 则不处理
        if (!StringUtils.containsAny(type.getSqlTemplate(),
          Arrays.stream(dataColumn.key()).map(key -> "#" + key).toArray(String[]::new)
        )) {
          continue;
        }
        // 设置注解变量 key 为表达式变量 value 为变量值
        for (int i = 0; i < dataColumn.key().length; i++) {
          context.setVariable(dataColumn.key()[i], dataColumn.value()[i]);
        }

        // 解析sql模板并填充
        String sql = parser.parseExpression(type.getSqlTemplate(), parserContext).getValue(context, String.class);
        conditions.add(joinStr + sql);
        isSuccess = true;
      }
      // 未处理成功则填充兜底方案
      if (!isSuccess && StringUtils.isNotBlank(type.getElseSql())) {
        conditions.add(joinStr + type.getElseSql());
      }
    }

    if (CollUtil.isNotEmpty(conditions)) {
      String sql = StreamUtils.join(conditions, Function.identity(), "");
      return sql.substring(joinStr.length());
    }
    return "";
  }

  private DataColumn[] findAnnotation(String mappedStatementId) {
    try {
      StringBuilder sb = new StringBuilder(mappedStatementId);
      int index = sb.lastIndexOf(".");
      String clazzName = sb.substring(0, index);
      String methodName = sb.substring(index + 1, sb.length());
      Class<?> clazz = ClassUtil.loadClass(clazzName);
      List<Method> methods = Arrays.stream(ClassUtil.getDeclaredMethods(clazz))
        .filter(method -> method.getName().equals(methodName)).toList();
      DataPermission dataPermission;
      // 获取方法注解
      for (Method method : methods) {
        dataPermission = dataPermissionCacheMap.get(mappedStatementId);
        if (ObjectUtil.isNotNull(dataPermission)) {
          return dataPermission.value();
        }
        if (AnnotationUtil.hasAnnotation(method, DataPermission.class)) {
          dataPermission = AnnotationUtil.getAnnotation(method, DataPermission.class);
          dataPermissionCacheMap.put(mappedStatementId, dataPermission);
          return dataPermission.value();
        }
      }
      dataPermission = dataPermissionCacheMap.get(clazz.getName());
      if (ObjectUtil.isNotNull(dataPermission)) {
        return dataPermission.value();
      }
      // 获取类注解
      if (AnnotationUtil.hasAnnotation(clazz, DataPermission.class)) {
        dataPermission = AnnotationUtil.getAnnotation(clazz, DataPermission.class);
        dataPermissionCacheMap.put(clazz.getName(), dataPermission);
        return dataPermission.value();
      }
      return null;
    } catch (Exception utilException) {
      return null;
    }
  }

  /**
   * 是否为无效方法 无数据权限
   */
  public boolean isInvalid(String mappedStatementId) {
    return invalidCacheSet.contains(mappedStatementId);
  }
}
